/Engine/Plugins/Runtime/GameplayAbilities/Source/GameplayAbilities/Public/AbilitySystemGlobals.h
Returns whether the specified gameplay mod evaluation channel is valid for use or not. Considers whether channel usage is allowed at all, as well as if the specified channel has a valid alias for the game.
bool IsGameplayModEvaluationChannelValid ( [EGameplayModEvaluationChannel](API\Plugins\GameplayAbilities\EGameplayModEvaluationChannel) Channel ) const